<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>dblink_fetch</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REV="MADE"
HREF="mailto:pgsql-docs@postgresql.org"><LINK
REL="HOME"
TITLE="PostgreSQL 9.1.2 Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="dblink"
HREF="dblink.html"><LINK
REL="PREVIOUS"
TITLE="dblink_open"
HREF="contrib-dblink-open.html"><LINK
REL="NEXT"
TITLE="dblink_close"
HREF="contrib-dblink-close.html"><LINK
REL="STYLESHEET"
TYPE="text/css"
HREF="stylesheet.css"><META
HTTP-EQUIV="Content-Type"
CONTENT="text/html; charset=ISO-8859-1"><META
NAME="creation"
CONTENT="2011-12-01T22:07:59"></HEAD
><BODY
CLASS="REFENTRY"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="5"
ALIGN="center"
VALIGN="bottom"
><A
HREF="index.html"
>PostgreSQL 9.1.2 Documentation</A
></TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
TITLE="dblink_open"
HREF="contrib-dblink-open.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="dblink.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="60%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="20%"
ALIGN="right"
VALIGN="top"
><A
TITLE="dblink_close"
HREF="contrib-dblink-close.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="CONTRIB-DBLINK-FETCH"
></A
>dblink_fetch</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN131050"
></A
><H2
>Name</H2
>dblink_fetch&nbsp;--&nbsp;returns rows from an open cursor in a remote database</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN131053"
></A
><H2
>Synopsis</H2
><PRE
CLASS="SYNOPSIS"
>dblink_fetch(text cursorname, int howmany [, bool fail_on_error]) returns setof record
dblink_fetch(text connname, text cursorname, int howmany [, bool fail_on_error]) returns setof record</PRE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN131055"
></A
><H2
>Description</H2
><P
>    <CODE
CLASS="FUNCTION"
>dblink_fetch</CODE
> fetches rows from a cursor previously
    established by <CODE
CLASS="FUNCTION"
>dblink_open</CODE
>.
   </P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN131060"
></A
><H2
>Arguments</H2
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="PARAMETER"
>conname</TT
></DT
><DD
><P
>       Name of the connection to use; omit this parameter to use the
       unnamed connection.
      </P
></DD
><DT
><TT
CLASS="PARAMETER"
>cursorname</TT
></DT
><DD
><P
>       The name of the cursor to fetch from.
      </P
></DD
><DT
><TT
CLASS="PARAMETER"
>howmany</TT
></DT
><DD
><P
>       The maximum number of rows to retrieve. The next <TT
CLASS="PARAMETER"
>howmany</TT
>
       rows are fetched, starting at the current cursor position, moving
       forward. Once the cursor has reached its end, no more rows are produced.
      </P
></DD
><DT
><TT
CLASS="PARAMETER"
>fail_on_error</TT
></DT
><DD
><P
>       If true (the default when omitted) then an error thrown on the
       remote side of the connection causes an error to also be thrown
       locally. If false, the remote error is locally reported as a NOTICE,
       and the function returns no rows.
      </P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN131084"
></A
><H2
>Return Value</H2
><P
>    The function returns the row(s) fetched from the cursor.  To use this
    function, you will need to specify the expected set of columns,
    as previously discussed for <CODE
CLASS="FUNCTION"
>dblink</CODE
>.
   </P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN131088"
></A
><H2
>Notes</H2
><P
>    On a mismatch between the number of return columns specified in the
    <TT
CLASS="LITERAL"
>FROM</TT
> clause, and the actual number of columns returned by the
    remote cursor, an error will be thrown. In this event, the remote cursor
    is still advanced by as many rows as it would have been if the error had
    not occurred.  The same is true for any other error occurring in the local
    query after the remote <TT
CLASS="COMMAND"
>FETCH</TT
> has been done.
   </P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN131093"
></A
><H2
>Examples</H2
><PRE
CLASS="SCREEN"
>SELECT dblink_connect('dbname=postgres');
 dblink_connect
----------------
 OK
(1 row)

SELECT dblink_open('foo', 'select proname, prosrc from pg_proc where proname like ''bytea%''');
 dblink_open
-------------
 OK
(1 row)

SELECT * FROM dblink_fetch('foo', 5) AS (funcname name, source text);
 funcname |  source
----------+----------
 byteacat | byteacat
 byteacmp | byteacmp
 byteaeq  | byteaeq
 byteage  | byteage
 byteagt  | byteagt
(5 rows)

SELECT * FROM dblink_fetch('foo', 5) AS (funcname name, source text);
 funcname  |  source
-----------+-----------
 byteain   | byteain
 byteale   | byteale
 bytealike | bytealike
 bytealt   | bytealt
 byteane   | byteane
(5 rows)

SELECT * FROM dblink_fetch('foo', 5) AS (funcname name, source text);
  funcname  |   source
------------+------------
 byteanlike | byteanlike
 byteaout   | byteaout
(2 rows)

SELECT * FROM dblink_fetch('foo', 5) AS (funcname name, source text);
 funcname | source
----------+--------
(0 rows)</PRE
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="contrib-dblink-open.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="contrib-dblink-close.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>dblink_open</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="dblink.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>dblink_close</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>